Hundreds of police are searching for the man dressed in white seen pushing a luggage trolley through the airport shortly before the bomb blasts. He was pictured in CCTV footage with two other suspects who are believed to have been killed in the carnage.

Investigators have used surveillance video to track the movements of the three men seen in the photo. The three are seen leaving a taxi and moving through the airport.

The third man, dressed in white, left the airport after accompanying the two. Investigators have told the media that that appeared to be planned and that the third man was acting as a guide to make sure the other two men carried out the attacks.

Brussels police are hunting for this man. Picture Getty/Fairfax

Briefing the media, Belgian prosecutor Frederic Van Leeuw said searches were taking place ‘in several parts of the country'. An explosive device containing nails, chemical products and an Islamic State flag were found in an apartment in the Schaerbeek area of Brussels.

The explosions happened in quick succession shortly after 8am local time, with some people being hit by the second blast as they tried to escape the first.

Another bomb was later found and destroyed in a controlled detonation at the scene.

Belgian officials put the death toll from both attacks at over 30, with at least 11 killed at the airport and about 20 in a separate attack on a metro station. Almost 200 people have been injured.

Two men in black, who were photographed pushing trolleys laden with luggage next to the man in white, are believed to have been suicide bombers killed in twin blasts, according to the federal prosecutor.

The attackers had travelled to the airport by taxi with the bombs inside suitcases, Zaventem Mayor Francis Vermeiren said.

“They placed their suitcases on carts once in the airport,” he said. “Two of the bombs exploded. The third attacker also placed his suitcase on a cart but he must have panicked because his bomb didn’t go off.”

Local media said police had found an undetonated suicide vest in the area.

Authorities believe at least one suspect in the attacks remains on the run. Agents conducted raids across the country on Tuesday, according to Belgium’s federal prosecutor.

Six hundred additional police have been deployed, many of them going door-to-door throughout Brussels searching for suspects or others planning attacks.